Hi Pancio,
Oh that would be great. XL or XE version is both okay for me. It really does not matter a lot to me.
If your colleague could make a few units for me, I would be more than welcome. If you know more, please let me know. I am ready to pay money, so let me know how we can do this.
If I remember correctly I built 20 years ago a SIO version of a Midi interface. It was with an OPTO-COUPLER component. It worked pretty well, but I lost my interest a bit because I had not much space in my room to have all kind of MIDI equipment connected to the Atari 8bit. Your device has a sound chip onboard which is great. I could use a way smaller keyboard then.
Well it is all very interesting.
Keep me updated please! Your invention is amazing. I really think many people will be interested, so perhaps you should contact Panos from Greece (you can find him on Atari Age) he has done amazing things for me in the past. So perhaps this is an idea?
Greetings, Marius from TheNetherlands.